1. Field of the Invention
The present general inventive concept relates to a hard disc drive (HDD) apparatus, and more particularly, to an apparatus and method of setting up a bit error rate (BER) criterion to examine a quality of a HDD, and an apparatus and method of performing a burn-in test of the HDD.
2. Description of the Related Art
Hard disc drives are data storage devices employed in electronic devices such as computers, MP3 players, or mobile phones. Conventionally, data are recorded on concentric tracks formed on a surface of a magnetic disc, which is a data storage medium in a hard disc drive (HDD). The magnetic disc is mounted to be able to rotate at a high speed on a spindle motor, and data are reproduced or recorded by a magnetic head provided on an end of a head stack assembly (HSA). The magnetic head reproduces data by detecting magnetic changes of a particular track of the surface of the magnetic disc on which data are recorded. Also, when a write signal corresponding to the data is inputted to the magnetic head, a magnetic field is formed to magnetize a particular track of the surface of the disc, thereby, recording data on the particular track of the disc.
Conventionally, HDDs are manufactured through a part assembly process, a servo write process, a function test process, and a burn-in test process. When passing the burin-in test, the HDD are finally checked in terms of whether the manufactured HDDs have a defect or not before the manufacturing process of the HDDs is completed. In the part assembly process, parts of the HDD are assembled, and in the servo write process, a servo write pattern for controlling the rotation of the HSA is recorded on the disc. Also, in the function test process, part portions and circuit portions are coupled, and in the burn-in test process, parameters for driving the HDD are set-up, and products having poor data recording and reproducing performance are separated through various tests.
In the burn-in test process, a bit error rate (BER) which is an error rate of recording/reproducing data of an HDD is measured, and each of the HDDs must pass a certain level of BER to complete the manufacturing process. A criterion value of BER to determine a high quality and a low quality of the HDD is a BER criterion. However, in the conventional burn-in test process, a certain BER criterion is used according to the type of HDDs regardless of a temperature of the HDDs. Thus, if the temperature of the HDD is higher than an optimum temperature for the burn-in test, substantially low quality products are classified as high quality products, thereby reducing performance reliability of the products. Also, if the temperature of the HDD is lower than the optimum temperature for the burn-in test, substantially high quality products are classified as low quality products, thereby reducing productivity and increasing manufacturing costs.